Ireneusz Jabłoński

Preliminary study on the accuracy of respiratory input impedance measurement using the interrupter technique

Respiratory input impedance contains information about the state of pulmonary mechanics in the frequency domain. In this paper the possibility of respiratory impedance measurement by interrupter technique as well as the accuracy of this approach are assessed. Transient states of flow and pressure recorded during expiratory flow interruption are simulated with a complex, linear model for the respiratory system and then used to calculate the impedance, including three states of respiratory mechanics and the influence of the measurement noise. The results of computations are compared to the known, theoretical impedance of the model. At 1 kHz sampling rate, the optimal time window lays between 100 and 200 ms and is centred around the pressure jump caused by the flow interruption. The proposed algorithm yields satisfactory accuracy in the range from 10 to 400 Hz, particularly to 150 Hz. Depending on the simulated respiratory system state, the error of calculated impedance (relative Euclidean distance between the vectors of computed and theoretical values), for the window of 190 ms, varies between 5.0% and 7.1%.

A Distributed Telemedical System for Monitoring of the Respiratory Mechanics by Enhanced Interrupter Technique

The chapter presents the development of a telemedical system. Works have been focused on algorithmic, applied hardware, software and transmission solutions. Modification of classical interrupter method, dedicated to the respiratory mechanics evaluation, has been postulated as a starting point for the whole project. It assumes exploitation of post-occlusional transients states in indirect measurement of physiological properties by solution of the inverse problem, where pressure and flow signals are pre-processed and then fitted to the outputs of reduced model in the time and/or frequency domain. The system consists of a base unit managing users and other devices as well as data transmission, processing, storage and presentation. It co-operates with home-based patient units capable of performing occlusional manoeuvres, tests. All the elements communicate via the Internet, wire or mobile telephony.

Development of a Telemedical System for Monitoring Patients with Chronic Respiratory Diseases

The development of a telemedicine system is presented focusing on applied hardware, software and data transmission solutions. The system consists of a base unit managing users and other devices as well as data transmission, processing, storage and presentation. It cooperates with homebased patient units capable of performing lung function tests. All the elements communicate via the Internet, however other media, as wire and mobile telephony, can be also used in regions with poorly developed infrastructure.

Reduction of a linear complex model for respiratory system during Airflow Interruption

The paper presents methodology of a complex model reduction to its simpler version - an identifiable inverse model. Its main tool is a numerical procedure of sensitivity analysis (structural and parametric) applied to the forward linear equivalent designed for the conditions of interrupter experiment. Final result - the reduced analog for the interrupter technique is especially worth of notice as it fills a major gap in occlusional measurements, which typically use simple, one- or two-element physical representations. Proposed electrical reduced circuit, being structural combination of resistive, inertial and elastic properties, can be perceived as a candidate for reliable reconstruction and quantification (in the time and frequency domain) of dynamical behavior of the respiratory system in response to a quasi-step excitation by valve closure.

Internal validation of a telemedical system for monitoring patients with chronic respiratory diseases

One of the most promising and innovative developments in medicine are telemedical systems. The system PulmoTel 2010 and its internal validation are presented, focusing on the system architecture, hardware, software and communication solutions. PulmoTel 2010 consists of a distant server managing users and medical devices, as well as data transmission, processing, storage and presentation. The server cooperates with home units used by patients, capable of performing lung function tests. All the elements communicate via the Internet, however other media, as wire and mobile telephony, can be additionally applied in regions with a less developed infrastructure. Internal validation of the system was performed using data generated by application simulating features of a home unit. It demonstrated an appropriate operation of the overall system and fulfillment of the main objectives of the project.

Smart Transducer Interface—From Networked On-Site Optimization of Energy Balance in Research-Demonstrative Office Building to Smart City Conception

This paper reviews the development and technical infrastructure of an energy-efficient research-demonstrative office building created by the Center for Energy Technology [in polish: Centrum Technologii Energetycznych (CTE)] in Swidnica. This modern structure offers multiple solutions for relevant research topics, such as energy generation, distribution, and preservation. The key contribution of the CTE team was to craft a fusion algorithm that could identify the optimal temporal system conditions, translate them into control system settings, and, through feedback, monitor the energy management processes for the site. Although exemplary results have been observed for the single year depicted in this paper, several years of future installation monitoring are planned. The conclusions obtained from this paper will be formulated as recommendations for researchers, designers, installers, and users of energy-efficient office buildings. The prospective initiatives of the CTE team have also been outlined. The implementation of ISO/IEC/IEEE 21451-x standards has been proposed as an effective tool for scaling this system from the smart-building level up to a smart-city platform.

Properties of Occlusional Devices in Extended Time–Frequency Analysis of Post-Interrupter Respiratory Signals

The usefulness of popular occlusional heads to extended, time-frequency analysis of post-interrupter respiratory data was tested in this study. A portable mobile interrupter module, designed to acquire (also in telemedical system) raw signals of mouth pressure (Qao) and airflow (Pao), enabled flexible valve operation during normal breathing and flow induced by the airflow generator. The potential for algorithmic development of data processing procedures and hardware limitations of the shutter-type valve by Jaeger and Micro Medical is depicted here. The power spectrum density of Pao and input interrupter impedance (Zint), calculated by the Micro Medical interrupter, were sensitive indices of respiratory mechanics measurement, but problematic natural oscillations and leakage during valve closing reduced the clinical relevance of the assessments. These hardware specifications represent prerequisites for prospective research in a sensing technology domain on an optimal valve-transducer unit design.

Measurement of Respiratory Input Impedance Using the Interrupter Technique – A Model Study

Abstract Respiratory input impedance contains information about the state of pulmonary mechanics in the frequency domain. In this paper the possibility of respiratory impedance measurement by interrupter technique as well as the accuracy of this approach are assessed. Transient states of flow and pressure recorded during expiratory flow interruption are simulated with a complex model for the respiratory system and then used to calculate the impedance. The results of computations are compared to the known impedance of the model, showing that the proposed algorithm yields satisfactory accuracy from 10 to 400 Hz, particularly in the range between 20 and 150 Hz.

Modern Methods for the Description of Complex Couplings in the Neurophysiology of Respiration

Breathing is a fundamental physiological process produced by movements generated and controlled by efferent signals from the nervous system. Improving our understanding of the mechanisms underlying breathing in humans is of particular interest. Another important practical issue is the design of noninvasive procedures for the diagnosis, prediction, and control of the respiratory system, which works as a subsystem embedded in the complex physiological environment of the human organism and its external environment. This paper provides a concise review of a selected set of modern techniques dedicated to the exploration of complex and varying systems and sets of time-series data. These methods are based on an 1D entropic tool (approximate and sample entropy, i.e., ApEn and SampEn, respectively), which is effective for assessing the regularity and complexity of information contained in data sets, as well as complex network theory, recurrence plot (RP) strategy, and the joint complex network-recurrence analysis mode. Exemplary results are given for real physiological data recorded in patients with symptoms of central sleep apnea syndrome. Although ApEn and SampEn are shown to be sensitive methods for the detection of pathological mechanisms affecting breathing patterns during sleep, qualitative and quantitative studies based on the RP strategy reveal even better efficiency for this task. In addition, the second mode of analysis enables multi-dimensional correlation of accessible data, which is important for studying the couplings between numerous physiological subsystems. Further work in this area is proposed to map the scheme of breathing physiology during sleep.

Wearable Interrupter Module for Home-Based Applications in a Telemedical System Dedicated to Respiratory Mechanics Measurements

The mobile interrupter module, dedicated to the enhanced interrupter (EIT) measurement of respiratory mechanics in a home environment and capable of cooperation with a telemedical system, is presented. Characterized by noninvasiveness and minimal requirements regarding patient cooperation, the EIT algorithm is especially suitable for newborns, preschool children, and patients suffering from respiratory muscle impairment. Furthermore, this device enables access to raw data-without initial preprocessing-in a fully flexible measurement protocol (which is not available in any commercial apparatus), and the EIT procedure improves insight (the number and precision of assessed parameters) into the physiological system with respect to the classical occlusive methods.